Penetration of neuronal perikarya by capillaries in chronic limbic encephalitis.

In a case of chronic limbic encephalitis in a 57-year-old man many neurons in the pyramidal cell layer of the hippocampus bilaterally were penetrated by ingrowing capillaries. All gradations from slight to moderate indentation of the cell membranes to complete incorporation of the capillaries in the neuronal perikarya were observed. The penetrating capillaries retained their basement membranes. Because of the chronic inflammation there was extensive fibrous gliosis in Ammon's horn. This apparently had an immobilizing effect on these neurons; it is postulated that proliferating capillaries of the active inflammatory process were unable to displace local neurons and instead grew against and through their perikarya.